I find it hard to believe that a rifle scope tube have much flex in it. How much flex could there be without compromising the integrity of the tube, something in the order of 1/10,000"?
Have you tested what the Warne people told by mounting an old or inexpensive rifle scope?
Why bother to test?? That statement is a disqualifier for me.
What statement?
Why not test? He already has the rings and it wouldn't take most than 15 minutes to install an old or throw-away scope.
The entire tube flex explanation sounds like BS to me.